Applications such as video telephone, digital television, and interactive multimedia using such digital storage technology as CD-ROM, digital audio tape, and magnetic disk require digital video coding, or video compression, to achieve the necessary high data transfer rates over relatively low bandwidth channels. Various standards have been proposed for video coding. For example, standards have been adopted by the International Standards Organization ("ISO") involving the storage and transmission of still images and motion-based images. More specifically, continuous-tone still image applications are addressed by the JPEG standard, teleconferencing is addressed by the Px64 standard, and full-motion video is addressed by the MPEG standard. An application such as interactive multimedia running on a personal computer or workstation may well require implementations of some or all of these compression techniques, as well as other techniques for voice mail and annotation and for lossless data compression of arbitrary binary files to be stored to disk or communicated to other computers. Moreover, new compression algorithms and modifications of current compression algorithms will be developed. Different compression algorithms have different resolution, bandwidth, and frame rate requirements, which are best accommodated by a programmable vision processor rather than a multitude of separate, dedicated vision processors for each function.
While building block implementations of vision processors have met with some success, there is a continued need for a programmable, high performance, and low cost digital signal processing architecture suitable for stand-alone use in image and video compression and/or decompression systems. Programmability is desirable because of the wish to accommodate a variety of different existing algorithms, custom versions of existing algorithms, and future algorithms. High performance and low cost are desirable because of the price-performance demands of the highly competitive marketplace in which digital signal processing devices are sold.